I have cloned the ext4 subtree: git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git Then I tried to build it, first by making a .config file, and then running make. The make won't finish beacuse I am getting this "all warnings being treated as errors": In file included from help.c:12: subcmd-util.h: In function ‘xrealloc’: subcmd-util.h:58:31: error: pointer ‘ptr’ may be used after ‘realloc’ [-Werror=use-after-free] 58 | ret = realloc(ptr, 1); | ^~~~~~~~~~~~~~~ subcmd-util.h:52:21: note: call to ‘realloc’ here 52 | void *ret = realloc(ptr, size); | ^~~~~~~~~~~~~~~~~~ subcmd-util.h:56:23: error: pointer ‘ptr’ may be used after ‘realloc’ [-Werror=use-after-free] 56 | ret = realloc(ptr, size); | ^~~~~~~~~~~~~~~~~~ subcmd-util.h:52:21: note: call to ‘realloc’ here 52 | void *ret = realloc(ptr, size); | ^~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors make[5]: *** [/home/max/kernels/ext4/tools/build/Makefile.build:97: /home/max/kernels/build_ext4/tools/objtool/help.o] Error 1 Worth mentioning that trying to 'make' the mainline tree works fine. I have tried adding the -Wno-error flag but it didnt work and anyway I think I shouldn't attempt changing it at all in order to build. I would appreciate any help, I am a newbie, and I'd like to help fixing some bugs.